CO₂ capture is an important strategy to reduce greenhouse
gas emissions from anthropogenic fossil fuel combustion and other
industrial activities. Among the available CO₂ capture
methods, including absorption, adsorption, membrane separation, and
biofixation, absorption technology is the most mature for
post-combustion applications and is one of the few options for
retrofitting existing power plants. Amine scrubbing, the absorption
of CO₂ by concentrated amine solutions, has been used at
full-scale for capturing CO₂ from coal-fired power
plants.

A major concern for the implementation of amine-based
post-combustion CO₂ capture is the formation of
potentially carcinogenic nitrosamines and nitramines. These harmful
byproducts form from the reactions between amines and nitrogen
oxides (NOₓ) in the flue gas, or nitrite, the hydrolysis
product of NOₓ. Several nitrosamines were listed as probable
human carcinogens, with threshold levels in drinking water at low
nanograms per liter to impose 10 excess cancer risk.

This dissertation aims to address the risks of absorption-based
CO₂ capture technology associated with the formation of
nitrosamines and nitramines. First, we investigated nitrosamine
formation in the desorber unit from tertiary alkanoamines, which
are considered as alternatives to traditional amines for
CO₂ capture due to their lower energy requirement.
Kinetic modeling based on experimental results indicated that the
formation of nitrosamines increased with CO₂ loading,
but not amine concentration within the range relevant to
CO₂ capture. We identified for the first time the
preferential cleavage of 2-hydroxyethyl functional group from
tertiary alkanolamines, resulting in nitrosamines with higher
volatility that parents amines.

Currently, work is underway to evaluate the formation of
nitrosamines from “green solvents” amino acids and
ionic liquids under conditions relevant to both the absorber and
desorber of CO₂ capture systems. Both of these chemicals
exist as ionic species and hence feature low vapor pressure. In
addition, the tunable and designable nature of ionic liquids offer
more benefits in the selective absorption of CO₂. However,
the potential of these novel mixtures in forming nitrosamines and
nitramines have not been evaluated.

In addition, we are incorporating nitrosamine formation in Aspen
Plus simulator. While Aspen Plus is widely used to predict
CO₂ capture performance, its capacity in predicting byproduct
formation has not been explored. A customized module will provide a
process simulation for nitrosation and nitration, and serve as the
basis for evaluating the environmental impacts of absorption-based
CO₂ capture systems.

Research Highlights

The Institute of Bridge Engineering and MCEER received a
contract valued at up to $15M over a period of five years to
provide structural engineering services to the Federal Highway
Administration’s Office of Bridges and Structures.

A research team led by CSEE Professor Cemal Basaran received a
$800,000 grant from the Office of Naval Research to develop
graphene nanoribbons that may revolutionize how power is controlled
in ships, smartphones and other devices.

After a magnitude 7.8 earthquake hit Nepal in late April, CSEE
Assistant Professor Andreas Stavridis received an NSF grant to
travel to Nepal with a team of researchers to examine why certain
structures held up and others did not.

A UB study involving faculty members Adel Sadek and Qing He
examined how weather-related tweets can be analyzed to bolster
computer models that recommend safe driving speeds and routes
during inclement weather.

A research team led by CSEE Professor Andreas Stavridis recently
subjected an existing 10-story concrete warehouse in Utica, N.Y.,
to a series of shake tests in order to study the behavior of
archaic concrete structures under lateral loads.

CSEE researchers found that green algae blooms (orange strands
in the smaller picture) act as a barrier between UV radiation and
bacteria, such as salmonella (green dots), which allows organisms
to grow unheeded on Great Lakes beaches.